In biology, a phylum (plural: phyla) is a taxonomic rank below Kingdom and above Class. "Phylum" is equivalent to the botanical term division.
Although a phylum is often spoken of as if it were a hard and fast entity, no satisfactory definition of a phylum exists. In fact, a phylum is perhaps best described as a statement of taxonomic ignorance. Consequently the number of phyla varies from author to author. The relationship between different phyl...
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In biology, a phylum (plural: phyla) is a taxonomic rank below Kingdom and above Class. "Phylum" is equivalent to the botanical term division.
Although a phylum is often spoken of as if it were a hard and fast entity, no satisfactory definition of a phylum exists. In fact, a phylum is perhaps best described as a statement of taxonomic ignorance. Consequently the number of phyla varies from author to author. The relationship between different phyla is increasingly well known, and larger clades can be erected to contain many of the phyla.
Informally, phyla can be thought of as grouping animals based on general body plan, as well as developmental or internal organizations. For example, though seemingly divergent, spiders and crabs both belong to Arthropoda, whereas earthworms and tapeworms, similar in shape, are from Annelida and Platyhelminthes, respectively. Although the International Code of Botanical Nomenclature allows the use of the term "phylum" in reference to plants, the term ...
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